Bracelets, necklaces, belts, straps and similar objects are generally fastened in an adjustable manner in predetermined positions, which allow precise re-positioning, and which the user can adjust via the cooperation of a finger with one hole among a plurality of holes, or by hooking a pin onto a rack, or a similar device. Continuous fastenings which maintain position using friction do not offer the possibility of precise re-positioning.
It is often necessary to have an adjustable length fastening, for example between two predetermined positions, to take account of climatic factors or the morphology or comfort of the user.
CH Patent No 699067 in the name of ELFIX PRODUCTION SA discloses a device for finely adjusting the length of a bracelet integrated in a clasp cover, and comprising a device for indexing in two predefined positions, and which includes spring ball push buttons, which are captived to a transverse bar, connected to one end of the bracelet and arranged to cooperate with pierced holes provided in the clasp cover.
EP Patent No 0 737 427 in the name of THE SWATCH GROUP MANAGEMENT SERVICES AG and CH Patent No 695 656 in the name of WERTHANOR SA disclose adjustable links for watch wristlets or bracelets, wherein adjustment is performed by actuating an unlocking button to change from one length indexing position to another.
FR Patent No 2 670 995 in the name of PERILLAT COLOMB discloses a bar which extends in the longitudinal direction of a bracelet, and whose ends are each engaged in a link portion in predefined indexing positions, either by spring bars, or by studs cooperating with holes provided in the bar. A tool has to be used to change from one position to another. These indexing devices extend transversely and require a significant amount of space. They are also visible and detract from the general attractiveness of the bracelet.
These known devices act transversely, generally require a tool to perform the adjustment, and remain visible.